Ghetto mod electric bike - a bit of a BLOG

[Tanis8472]

Aiming for 2.5hp on something weighing maybe 125kg including rider

20hp per ton. That should go like snot

 

[BenScoobert]

Aiming for 2.5hp on something weighing maybe 125kg including rider

20hp per ton. That should go like snot

Right now it is about 113kg me + 25kg bike with 1kw/1.34bhp
it propels me to 27mph in no time, the gearing on this bike doesn't allow pedalling over 20 mph, I found a sweet spot is to limit it to 16.5mph.

I still need a crank puller to fit the cadence sensor

 

[BenScoobert]

Well done for getting up and running.

Fitting a kit requires some creative fettling.

Fine if you know what you are doing, but it would defeat a lot of us.

I see you also seem to know what you are doing with batteries, which is another big plus.

The fitment was fairly straight forward TBH, the cyclotricity kit seems quite simplified compared to some.

As for the batteries, I have radio controlled helicopters, the batteries I use are capable of delivering about 2.5kw each, so this is a walk in the park for them.
That's the difference between lithium ion and lithium polymer, on the downside they are far more volatile and subject to careful charging.
Each of my packs is 5AH 25.2v (6S) that means 6x 4.2v cells in serial. I used 2 packs to give me a theoretical max of 50.4v in 12S.
Then I plan to run pairs on packs in parallel which will up my AH, to if I use 4 pairs of packs I'll have 20AH.
20AHx50.4v = 1008WH this is 1.008KWH meaning I can run 1KW for an hour and fully drain the packs, or a 4 hour 250w discharge.

I wouldn't drain the packs fully as it doesn't do them any good, a good rule of thumb is 80% discharge. Which ties up nicely with the low voltage cut off of the kit.

 

[BenScoobert]

This is now for sale in the classified section